摘要
星间相干光通信系统中,信号光与本振光的不同分布将影响外差混频效率。在假设信号光与本振光偏振一致、相位匹配、几何中心重合的前提下,详细推导了信号光振幅为平面波(Uniform)、高斯(Gauss)分布,本振光为艾里斑(Airy)、Uniform及Gauss分布时的6种外差混频效率关系式,其中4种得到了精确的解析式。在此基础上,通过数值仿真,全面对比分析了各种组合的外差混频性能,结果发现,Airy+Airy和Gauss+Gauss具有最佳外差混频性能,理论上可以达到100%外差混频效率;Uniform+Uniform的最大外差混频效率为72%,Guass+Uniform最大外差混频效率是82%,它们具有相似性;而Airy+Gauss组合是系统中常用的分布模型,其外差混频效率同时受探测器半径及Gauss束腰的制约。这将为设计星间相干通信系统提供必要的理论依据。
The difference of amplitude profile between signal and local oscillator wave will affect the heterodyne efficiency of the inter-satellite coherent optical communication system.Based on the assumption that signal and local oscillator wave have the same polarization and geometric center,and that they are phase matching,the detailed derivation of heterodyne efficiency is given when the signal has uniform or Gauss distributions,and the local oscillator wave has Airy,uniform or Gaussan distributions.The accurate analysis formulas of heterodyne efficiency are presented for some different signal and local oscillator wave distributions.The performance of heterodyne photomixing for different signal and local oscillator wave distributions are completely given by using the numerical calculations and comparative analysis method.The results indicate that the Airy＋Airy and Gauss＋Gauss cases have the optimal heterodyne performance,the heterodyne efficiency can reach 100%;the values of heterodyne efficiency for the Airy＋Uniform and Gauss＋Uniform cases are 72% and 82%,respectively,which are similar.The Airy＋Gauss case is restricted by the detector radius and the Gaussian beam′s waist radius at the same time,and it is usually used in the actual system.These provide some theoretic principles for designing the inter-satellite coherent optical communication system.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2011年第10期63-68,共6页
Acta Optica Sinica
基金
国家863计划(2009AA01Z256
2009AA01Z253
2009AA01A345)
中国博士后基金(20100470257)
中国科学院空间激光通信及检验技术重点开放实验室(KFKT2009-03)资助课题
关键词
光通信
星间相干光通信
相干接收
外差效率
optical communications
inter-satellite coherent optical communication
coherent receiver
heterodyne efficiency
